feat(runapi): add RunStepList response args https://platform.openai.com/docs/api-reference/runs/listRunSteps (#573)

run.go

@@ -157,6 +157,10 @@ type StepDetailsToolCalls struct {
 type RunStepList struct {
 	RunSteps []RunStep `json:"data"`
 
+	FirstID string `json:"first_id"`
+	LastID  string `json:"last_id"`
+	HasMore bool   `json:"has_more"`
+
 	httpHeader
 }